Padawan Lesson: Systemic Interaction

A healthy human system is not all that fragile. Resilience and robustness are byproducts of complexity. It is only when a system cannot cope with environmental and task demands that the system simplifies itself and appears to be fragile.

A narrowed example to explain a broader perspective…

According to Zatsiorsky,  we have 230 joints controlled by 630 muscles resulting in 244 degrees of freedom (  While the structural constraints represent limitations on our movement capacity, it also represents tremendous redundancy in our movement system.  As long as we remain within the limits of our capacity and respect the normal constraints of the human movement system, we tend to move through the world successfully with seemingly no internal awareness or concerns.

We have degeneracy built throughout our system meaning that we have multiple structures that while different can perform similar tasks resulting in successful outcomes.  Consider the concepts of muscle chains or coordinative structures. These are structures that work together to produce a specific outcome.

To focus on the muscles, if we perform some sort of repetitive task we know the sequence of activity and timing within the muscles can vary from repetition to repetition even though the end result may appear perfectly consistent to the naked eye. If any single muscle in the coordinative structure should experience fatigue, the remaining muscles are capable of picking up the slack and maintaining the intended level performance. It is only when capacity is reduced or exceeded, such as the case of fatigue or perhaps some other centrally-driven emergent behavior, the system is no longer capable of reciprocal compensation (the ability to shift demands to different components of a muscle synergy for example).

At this point, I think the system would move into a more defensive strategy to protect itself against the now threatening demands of the task and environment. As I’ve mentioned before I think this is where we’ll see a simplification or a reduction of the complexity of the system, in this case the reduction of the degrees of freedom of the movement system. Many movement professionals would see this as dysfunctional movement at this point. Keep in mind that my opinion is that humans are not machines, and therefore, behaviors are purposeful based on perceptions whether or not they are real, accurate, or adaptive.

This isn’t limited to just the movement system as I think all aspects of an integrated system would respond in a self-organizing manner. Consider outputs of the central nervous system such as anxiety (increase energy output and vigilance in response to threat), depression or fatigue (reduction in energy output and conservation in response to threat), and pain (salience detection in response to threat). I see these as defenses to reduce the degrees of freedom or the variability of the possible behaviors (in this case psychological) generated from the central nervous system.

Scope of practice limits how we will approach restoration of variability, resiliency, redundancy, and capacity to the system. As movement professionals, we obviously observe the human system via its structural constraints (biomechanics) with consideration to the adaptability of functional constraints (neuro, psych, endocrine, immune, etc.), but we must also concern ourselves with how we interact verbally and nonverbally.  I’m not recommending that movement professionals try to turn themselves into amateur psychologists or supersede the recommendations of a medical doctor. I’m merely stating that we need to consider that the entire system responds in similar ways by simplifying, conserving, and redirecting resources to survive.

How you interact with the system on all levels matters and determines a successful outcome.













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